dgsholar

I was able to buy my next door neighbor's (true little old lady) 2010 RX 350 AWD with less than 25,000 miles on it. She truly only drove it twice a week, once to church and once to the grocery store. Amazingly she kept all the maintenance records. All she's ever done is one or two recalls and oil changes. No Diff changes, no coolant changes, nothing but oil.

Does anyone have recommendations on what I should do to keep this running well? It's been a full 10 years since she bought it. So does it really need front, rear diff & transfer fluids changed? Should I do the coolant too, due to age? I'm thinking yes to all, but welcome advice. This is my first Lexus, first Toyota of any kind unless you count a GEO Prisim I had in the 90's.

Thanks for any and all help. This looks like a great forum. I'll be digging into the tranny section and others as I get to know this RX 350.

Clutchless

Congratulations on such a great find and welcome to CL! My sister found one of those once, an 8 year old Honda Civic with 17,000 miles owned by another old lady. Her daughter was happy.

Because it is 10 years old you should change all the lubricants, coolant and brake fluid. Make sure they service the brakes and lubricate the slide pins as they probably have never been touched and are the original pads.
If it has the tow package make sure they change the rubber oil cooler lines for the metal replacement ones. This repair is under $300 and will save you from engine failure due to a sudden violent rapid oil leak.
You may want to consider a transmission fluid drain and fill, but could possibly wait until 50,000 miles for that. If it was my car I would do it now while doing all the other lubricants etc.
It has electric power steering, so not fluid to change there.
Check if the rear shocks are leaking, you can tell if the lower halves are wet looking or darker in color. You can buy OEM replacements or KYB and it is a simple 2 bolt process to replace them.
Check the dates on the tires and if they are over 7 years old replace them.
Check and probably replace the engine air and cabin air filters.
Many dealers offer packages to change all the lubricants etc, and you can take this to either a Toyota or Lexus dealer as the RX350 is a mechanical twin to the Toyota Highlander. You can even shop prices if you have several of them in your area.
Wherever you go make sure they only use Toyota Super Long Life Coolant and Toyota WS Automatic Transmission Fluid. All the other lubricants can be any brand.
Enjoy your new ride!

dgsholar

Great - thanks for the tips. I didn’t know you could change the transmission fluid. I was going to attempt the differentials my self, and transfer case.

thanks especially for the tip on coolant lines.

N4wwt

Due to years, do it all and you’ll be good for the next 100k miles! Tires should also be replaced probably due to dry rot. Enjoy!

Clutchless

You can identify if you have the tow package by looking at the driver side front tire wheel well. If the front part of the inner fender liner has vents, they are for the auxiliary transmission cooler and you have the tow package. Look under the engine and next to the oil filter you will see the oil cooler hoses which are either black if rubber or all shiny metal if replaced.
FYI since you are a shade tree mechanic, the Toyota Nation Highlander site (2008-2013) has tons of DIY maintenance information and except for trim covers, it is the same as the RX. Here is the link
https://www.toyotanation.com/forums/...2008-2013.122/

dgsholar

Thanks Clutchless - is there a separate front diff and transfer case and both need to be drained and refilled? My other vehicle is a Jeep Wrangler Rubicon and front/rear/transfer are all separate and must be changed independently.

Yes, I have the tow package and my oil cooler lines have not been upgraded to metal - THANKS for that huge tip - doing that soon, either self or dealer (call pending for pricing). Tires are OE, so almost 11 years old. New ones tomorrow.

Am I able to refill transmission? I found the drain plug, but no fill plug...

I truly appreciate the help. This is a very different car for me and way out of my experience.

salimshah

One of the nice thing about group sourcing is that you get different opinions.

My 2c would be gradually make changes as you get to the new normal. Lot of fluids have a long shelf life. Brake fluid would be on my list to change along with check of slider pins. Trans fluid change is a controversial issue. I would leave it alone well over 60k miles [but that is just me]. Check the expiration date on tires. I also favor doing one thing at a time to contain issues. This may fit my DIY process as I dont have to drop off the vehicle repeated times.

As some one put a good work horse needs to be used judiciously. Overwork it or underwork it, are both bad.

Above all, enjoy the new purchase.

Salim

dgsholar

Thanks Salim, I didn’t know tires had an expiration date. These are 11 years old - original. They have small cracks all along sidewalls and between the treads on the circumference of the tires. I’m hearing about catastrophic failures on some tires due to age and tread separation. Checked the oil cooler hoses, no cracks at all, looks very healthy - but from what I’ve read here and other places these hoses can also go suddenly.

I like your idea of going slow and that way I can identify if a mistake has been made. Thank You.

tom93r1

Brake fluid, coolant, and tires (all rubber parts eventually) are the main things that will just go bad with time and I'd change immediately.
If it were me, everything else I'd continue to go by the recommended service interval in the manual unless you just have extra time and need projects.

dgsholar

Changed out Oil Cooler line today DYI. Called dealer for price this AM, nothing heard. Had to chop a 12mm box wrench to 1/3 to get one of the bolts tightened. All good no leaks. Partial drain/refill of coolant. Oil Change, filter change. New tires tomorrow and brake fluid bleed. Diff fluid on the way. Thanks everyone.

Still wondering if front diff and transfer case are in same unit or separate? Or is there no front diff per se, since it’s front wheel drive normally unless rear is needed or manually set?

Anyone know about front differential and transfer case?

Thanks again! I really appreciate the support and advice.

Clutchless

Congratulations on doing the oil cooler tube replacement, if I had known you were going ahead I would have advised that the trick is to remove some of the bolts as it makes installation easier. A small Torx socket will unscrew them.

Front differential is part of the transmission. The transfer case is separate and behind it.
Earlier when I said the 2nd gen Highlander was a twin, I should clarify that the RX has a different rear suspension with shocks, that sometimes leak.
The Highlander 2008-13 has rear struts. Later Highlanders have the same rear shock suspension as the RX.

Transmission fluid change has caused lots of arguments. There is a huge thread on it on the forum with lots of information and photos https://www.clublexus.com/forums/rx-...d-threads.html

Youtube has many videos on doing either a drain and fill which is my recommendation for someone at home, or a fluid exchange. Toyota removed the dipstick on this transmission design and instead has a very complicated system with an overflow tube and the requirement you check it at a certain temperature. I think they did it to provide dealers with more service work.
On Youtube start with a search for rx350 transmission fluid change. You will find many that discuss a fluid level check or drain and fill for the U660E transmission, which is the 6 speed.

You can do a cold (new fluid and car at same temperature) transmission drain and fill. After you remove the drain plug, inside the hole is the overflow tube that is also 6MM and plastic. About 2 quarts will drain out at most.
The fill hole is accessed by removing the driver side front tire, then there is a small flap in the lower front edge that covers it. I think it takes a 24MM socket. You will need a very long funnel, or clamp a hose to a funnel.
Or get the (search this title on eBay) Toyota & Lexus Sealed Transmission Fluid Replacement Kit
I installed this in my used 2013 Sienna and it works great. He has designed a new longer overflow tube that is calibrated for when the transmission is at normal operating temperature. So you just drive around, then let it idle on level ground for 5 minutes before checking the level per the instructions. He also has a fill tube that attaches to the hole and mounts inside the engine compartment so adding more fluid is very easy, as are future drain and fills.

dgsholar

Great - thanks again for excellent information. I picked up the Torx sockets and did have to remove 2 to get the installation complete. Thanks for the tip on the eBay kit, will check it out. Did brake fluid swap yesterday - really easy. Any ideas on how to update the navigation system maps?

Thanks again for all the help.

Clutchless

Unfortunately only the dealer can update the Navigation system and the cost varies between $200 and over $300. You may be better off using your phone and getting one of those cupholder or vent phone mounts.

dgsholar

Anyone know where to get a good service manual for the 2010 RX350 ?

Clutchless

Haynes has a repair manual for about $25. Amazon probably sells it, or eBay. Haynes is an old and well-regarded aftermarket source for repair manuals.

The factory manual costs a fortune. You can subscribe online to the Toyota Technical Information System for a short period of time to collect the information you need

https://techinfo.toyota.com/techInfo...tis&_nfpb=true

Someone on eBay is selling digital access to the service manual for 30 days for $6.95. They claim to have sold 159 of them.